code review 846043: Delete xgb from the main repository. It has moved to

src/pkg/xgb/xgb.go

Index: src/pkg/xgb/xgb.go
===================================================================
deleted file mode 100644
--- a/src/pkg/xgb/xgb.go
+++ /dev/null
@@ -1,464 +0,0 @@
-// Copyright 2009 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// The XGB package implements the X11 core protocol.
-// It is based on XCB: http://xcb.freedesktop.org/
-package xgb
-
-import (
-	"fmt"
-	"io"
-	"net"
-	"os"
-	"strconv"
-	"strings"
-)
-
-// A Conn represents a connection to an X server.
-// Only one goroutine should use a Conn's methods at a time.
-type Conn struct {
-	host          string
-	conn          net.Conn
-	nextId        Id
-	nextCookie    Cookie
-	replies       map[Cookie][]byte
-	events        queue
-	err           os.Error
-	display       string
-	defaultScreen int
-	scratch       [32]byte
-	Setup         SetupInfo
-}
-
-// Id is used for all X identifiers, such as windows, pixmaps, and GCs.
-type Id uint32
-
-// Cookies are the sequence numbers used to pair replies up with their requests
-type Cookie uint16
-
-type Keysym uint32
-type Timestamp uint32
-
-// Event is an interface that can contain any of the events returned by the server.
-// Use a type assertion switch to extract the Event structs.
-type Event interface{}
-
-// Error contains protocol errors returned to us by the X server.
-type Error struct {
-	Detail uint8
-	Major  uint8
-	Minor  uint16
-	Cookie Cookie
-	Id     Id
-}
-
-func (e *Error) String() string {
-	return fmt.Sprintf("Bad%s (major=%d minor=%d cookie=%d id=0x%x)",
-		errorNames[e.Detail], e.Major, e.Minor, e.Cookie, e.Id)
-}
-
-// NewID generates a new unused ID for use with requests like CreateWindow.
-func (c *Conn) NewId() Id {
-	id := c.nextId
-	// TODO: handle ID overflow
-	c.nextId++
-	return id
-}
-
-// Pad a length to align on 4 bytes.
-func pad(n int) int { return (n + 3) & ^3 }
-
-func put16(buf []byte, v uint16) {
-	buf[0] = byte(v)
-	buf[1] = byte(v >> 8)
-}
-
-func put32(buf []byte, v uint32) {
-	buf[0] = byte(v)
-	buf[1] = byte(v >> 8)
-	buf[2] = byte(v >> 16)
-	buf[3] = byte(v >> 24)
-}
-
-func get16(buf []byte) uint16 {
-	v := uint16(buf[0])
-	v |= uint16(buf[1]) << 8
-	return v
-}
-
-func get32(buf []byte) uint32 {
-	v := uint32(buf[0])
-	v |= uint32(buf[1]) << 8
-	v |= uint32(buf[2]) << 16
-	v |= uint32(buf[3]) << 24
-	return v
-}
-
-// Voodoo to count the number of bits set in a value list mask.
-func popCount(mask0 int) int {
-	mask := uint32(mask0)
-	n := 0
-	for i := uint32(0); i < 32; i++ {
-		if mask&(1<<i) != 0 {
-			n++
-		}
-	}
-	return n
-}
-
-// A simple queue used to stow away events.
-type queue struct {
-	data [][]byte
-	a, b int
-}
-
-func (q *queue) queue(item []byte) {
-	if q.b == len(q.data) {
-		if q.a > 0 {
-			copy(q.data, q.data[q.a:q.b])
-			q.a, q.b = 0, q.b-q.a
-		} else {
-			newData := make([][]byte, (len(q.data)*3)/2)
-			copy(newData, q.data)
-			q.data = newData
-		}
-	}
-	q.data[q.b] = item
-	q.b++
-}
-
-func (q *queue) dequeue() []byte {
-	if q.a < q.b {
-		item := q.data[q.a]
-		q.a++
-		return item
-	}
-	return nil
-}
-
-// sendRequest sends a request to the server and return its associated sequence number, or cookie.
-// It is only used to send the fixed length portion of the request, sendBytes and friends are used
-// to send any additional variable length data.
-func (c *Conn) sendRequest(buf []byte) Cookie {
-	if _, err := c.conn.Write(buf); err != nil {
-		fmt.Fprintf(os.Stderr, "x protocol write error: %s\n", err)
-		c.err = err
-	}
-	cookie := c.nextCookie
-	c.nextCookie++
-	return cookie
-}
-
-// sendPadding sends enough bytes to align to a 4-byte border.
-// It is used to pad the variable length data that is used with some requests.
-func (c *Conn) sendPadding(n int) {
-	x := pad(n) - n
-	if x > 0 {
-		_, err := c.conn.Write(c.scratch[0:x])
-		if err != nil {
-			fmt.Fprintf(os.Stderr, "x protocol write error: %s\n", err)
-			c.err = err
-		}
-	}
-}
-
-// sendBytes sends a byte slice as variable length data after the fixed portion of a request,
-// along with any necessary padding.
-func (c *Conn) sendBytes(buf []byte) {
-	if _, err := c.conn.Write(buf); err != nil {
-		fmt.Fprintf(os.Stderr, "x protocol write error: %s\n", err)
-		c.err = err
-	}
-	c.sendPadding(len(buf))
-}
-
-func (c *Conn) sendString(str string) { c.sendBytes([]byte(str)) }
-
-// sendUInt32s sends a list of 32-bit integers as variable length data.
-func (c *Conn) sendUInt32List(list []uint32) {
-	buf := make([]byte, len(list)*4)
-	for i := 0; i < len(list); i++ {
-		put32(buf[i*4:], list[i])
-	}
-	c.sendBytes(buf)
-}
-
-func (c *Conn) sendIdList(list []Id, length int) {
-	buf := make([]byte, length*4)
-	for i := 0; i < length; i++ {
-		put32(buf[i*4:], uint32(list[i]))
-	}
-	c.sendBytes(buf)
-}
-
-func (c *Conn) sendKeysymList(list []Keysym, length int) {
-	buf := make([]byte, length*4)
-	for i := 0; i < length; i++ {
-		put32(buf[i*4:], uint32(list[i]))
-	}
-	c.sendBytes(buf)
-}
-
-// readNextReply reads and processes the next server reply.
-// If it is a protocol error then it is returned as an Error.
-// Events are pushed onto the event queue and replies to requests
-// are stashed away in a map indexed by the sequence number.
-func (c *Conn) readNextReply() os.Error {
-	buf := make([]byte, 32)
-	if _, err := io.ReadFull(c.conn, buf); err != nil {
-		fmt.Fprintf(os.Stderr, "x protocol read error: %s\n", err)
-		return err
-	}
-
-	switch buf[0] {
-	case 0:
-		err := &Error{
-			Detail: buf[1],
-			Cookie: Cookie(get16(buf[2:])),
-			Id:     Id(get32(buf[4:])),
-			Minor:  get16(buf[8:]),
-			Major:  buf[10],
-		}
-		fmt.Fprintf(os.Stderr, "x protocol error: %s\n", err)
-		return err
-
-	case 1:
-		seq := Cookie(get16(buf[2:]))
-		size := get32(buf[4:])
-		if size > 0 {
-			bigbuf := make([]byte, 32+size*4, 32+size*4)
-			copy(bigbuf[0:32], buf)
-			if _, err := io.ReadFull(c.conn, bigbuf[32:]); err != nil {
-				fmt.Fprintf(os.Stderr, "x protocol read error: %s\n", err)
-				return err
-			}
-			c.replies[seq] = bigbuf
-		} else {
-			c.replies[seq] = buf
-		}
-
-	default:
-		c.events.queue(buf)
-	}
-
-	return nil
-}
-
-// waitForReply looks for a reply in the map indexed by sequence number.
-// If the reply is not in the map it will block while reading replies from the server
-// until the reply is found or an error occurs.
-func (c *Conn) waitForReply(cookie Cookie) ([]byte, os.Error) {
-	for {
-		if reply, ok := c.replies[cookie]; ok {
-			c.replies[cookie] = reply, false
-			return reply, nil
-		}
-		if err := c.readNextReply(); err != nil {
-			return nil, err
-		}
-	}
-	panic("unreachable")
-}
-
-// WaitForEvent returns the next event from the server.
-// It will block until an event is available.
-func (c *Conn) WaitForEvent() (Event, os.Error) {
-	for {
-		if reply := c.events.dequeue(); reply != nil {
-			return parseEvent(reply)
-		}
-		if err := c.readNextReply(); err != nil {
-			return nil, err
-		}
-	}
-	panic("unreachable")
-}
-
-// PollForEvent returns the next event from the server if one is available in the internal queue.
-// It will not read from the connection, so you must call WaitForEvent to receive new events.
-// Only use this function to empty the queue without blocking.
-func (c *Conn) PollForEvent() (Event, os.Error) {
-	if reply := c.events.dequeue(); reply != nil {
-		return parseEvent(reply)
-	}
-	return nil, nil
-}
-
-// Dial connects to the X server given in the 'display' string.
-// If 'display' is empty it will be taken from os.Getenv("DISPLAY").
-//
-// Examples:
-//	Dial(":1")                 // connect to net.Dial("unix", "", "/tmp/.X11-unix/X1")
-//	Dial("/tmp/launch-123/:0") // connect to net.Dial("unix", "", "/tmp/launch-123/:0")
-//	Dial("hostname:2.1")       // connect to net.Dial("tcp", "", "hostname:6002")
-//	Dial("tcp/hostname:1.0")   // connect to net.Dial("tcp", "", "hostname:6001")
-func Dial(display string) (*Conn, os.Error) {
-	c, err := connect(display)
-	if err != nil {
-		return nil, err
-	}
-
-	// Get authentication data
-	authName, authData, err := readAuthority(c.host, c.display)
-	if err != nil {
-		return nil, err
-	}
-
-	// Assume that the authentication protocol is "MIT-MAGIC-COOKIE-1".
-	if authName != "MIT-MAGIC-COOKIE-1" || len(authData) != 16 {
-		return nil, os.NewError("unsupported auth protocol " + authName)
-	}
-
-	buf := make([]byte, 12+pad(len(authName))+pad(len(authData)))
-	buf[0] = 0x6c
-	buf[1] = 0
-	put16(buf[2:], 11)
-	put16(buf[4:], 0)
-	put16(buf[6:], uint16(len(authName)))
-	put16(buf[8:], uint16(len(authData)))
-	put16(buf[10:], 0)
-	copy(buf[12:], []byte(authName))
-	copy(buf[12+pad(len(authName)):], authData)
-	if _, err = c.conn.Write(buf); err != nil {
-		return nil, err
-	}
-
-	head := make([]byte, 8)
-	if _, err = io.ReadFull(c.conn, head[0:8]); err != nil {
-		return nil, err
-	}
-	code := head[0]
-	reasonLen := head[1]
-	major := get16(head[2:])
-	minor := get16(head[4:])
-	dataLen := get16(head[6:])
-
-	if major != 11 || minor != 0 {
-		return nil, os.NewError(fmt.Sprintf("x protocol version mismatch: %d.%d", major, minor))
-	}
-
-	buf = make([]byte, int(dataLen)*4+8, int(dataLen)*4+8)
-	copy(buf, head)
-	if _, err = io.ReadFull(c.conn, buf[8:]); err != nil {
-		return nil, err
-	}
-
-	if code == 0 {
-		reason := buf[8 : 8+reasonLen]
-		return nil, os.NewError(fmt.Sprintf("x protocol authentication refused: %s", string(reason)))
-	}
-
-	getSetupInfo(buf, &c.Setup)
-
-	if c.defaultScreen >= len(c.Setup.Roots) {
-		c.defaultScreen = 0
-	}
-
-	c.nextId = Id(c.Setup.ResourceIdBase)
-	c.nextCookie = 1
-	c.replies = make(map[Cookie][]byte)
-	c.events = queue{make([][]byte, 100), 0, 0}
-	return c, nil
-}
-
-// Close closes the connection to the X server.
-func (c *Conn) Close() { c.conn.Close() }
-
-// DefaultScreen returns the Screen info for the default screen, which is
-// 0 or the one given in the display argument to Dial.
-func (c *Conn) DefaultScreen() *ScreenInfo { return &c.Setup.Roots[c.defaultScreen] }
-
-
-// ClientMessageData holds the data from a client message,
-// duplicated in three forms because Go doesn't have unions.
-type ClientMessageData struct {
-	Data8  [20]byte
-	Data16 [10]uint16
-	Data32 [5]uint32
-}
-
-func getClientMessageData(b []byte, v *ClientMessageData) int {
-	copy(&v.Data8, b)
-	for i := 0; i < 10; i++ {
-		v.Data16[i] = get16(b[i*2:])
-	}
-	for i := 0; i < 5; i++ {
-		v.Data32[i] = get32(b[i*4:])
-	}
-	return 20
-}
-
-func connect(display string) (*Conn, os.Error) {
-	if len(display) == 0 {
-		display = os.Getenv("DISPLAY")
-	}
-
-	display0 := display
-	if len(display) == 0 {
-		return nil, os.NewError("empty display string")
-	}
-
-	colonIdx := strings.LastIndex(display, ":")
-	if colonIdx < 0 {
-		return nil, os.NewError("bad display string: " + display0)
-	}
-
-	var protocol, socket string
-	c := new(Conn)
-
-	if display[0] == '/' {
-		socket = display[0:colonIdx]
-	} else {
-		slashIdx := strings.LastIndex(display, "/")
-		if slashIdx >= 0 {
-			protocol = display[0:slashIdx]
-			c.host = display[slashIdx+1 : colonIdx]
-		} else {
-			c.host = display[0:colonIdx]
-		}
-	}
-
-	display = display[colonIdx+1 : len(display)]
-	if len(display) == 0 {
-		return nil, os.NewError("bad display string: " + display0)
-	}
-
-	var scr string
-	dotIdx := strings.LastIndex(display, ".")
-	if dotIdx < 0 {
-		c.display = display[0:]
-	} else {
-		c.display = display[0:dotIdx]
-		scr = display[dotIdx+1:]
-	}
-
-	dispnum, err := strconv.Atoui(c.display)
-	if err != nil {
-		return nil, os.NewError("bad display string: " + display0)
-	}
-
-	if len(scr) != 0 {
-		c.defaultScreen, err = strconv.Atoi(scr)
-		if err != nil {
-			return nil, os.NewError("bad display string: " + display0)
-		}
-	}
-
-	// Connect to server
-	if len(socket) != 0 {
-		c.conn, err = net.Dial("unix", "", socket+":"+c.display)
-	} else if len(c.host) != 0 {
-		if protocol == "" {
-			protocol = "tcp"
-		}
-		c.conn, err = net.Dial(protocol, "", c.host+":"+strconv.Uitoa(6000+dispnum))
-	} else {
-		c.conn, err = net.Dial("unix", "", "/tmp/.X11-unix/X"+c.display)
-	}
-
-	if err != nil {
-		return nil, os.NewError("cannot connect to " + display0 + ": " + err.String())
-	}
-	return c, nil
-}